Ventilation exhaust fan with back draft preventer



y 1968 J. R. FULLER 3,384,000

VENTILATION EXHAUST FAN WITH BACK DRAFT. PREVENTER Filed July 11, 1966 2 Sheets-Sheet l zvmvrozz. JOSEPH R. FULLER llffarnex s J. R. FULLER May 21, 1968 VENTILATION EXHAUST FAN WITH BACK DRAFT PREVENTER 2 Sheets-Sheet 3 Filed July 11, 1966 1R. kw

United States Patent 3,384,000 VENTILATION EXHAUST FAN WITH BACK DRAFT PREVENTER Joseph R. Fuller, 7732 N. Sherman Drive, Indianapolis, Ind. 46240 Filed July 11, 1966, Ser. No. 564,360 3 Claims. (Cl. 98-43) ABSTRACT OF THE DISCLOSURE Ai ventilating apparatus incorporating a centrifugal blower wheel and constructed for mounting in the wall of a building. The apparatus includes a frame defining an opening through which air may be moved and having a plurality of louvers fixed to the frame in spaced relation. A plurality of back draft dampers are mounted on the louvers and each control a respective space between the louvers with a screen being provided as the backstop for the flexible back draft dampers.

The present invention relates to ventilating apparatus particularly adapted for mounting in the wall of a build- 1ng.

Many presently available exhaust fans must be mounted in the roof of a building. Because of the design of such exhaust fans, they make necessary an unsightly projection on the top of the building. Other exhaust fans are mounted in the wall of a building but still incorporate an unsightly projection extending outside of the building away from the wall of the building. One object of the present invention is to provide a ventilating apparatus adapted for Wall mounting and which presents a clean appearance flush with the outside wall of the building. Another object of the invention is to provide an improved ventilating apparatus.

Still another object of the invention is to provide a ventilating apparatus which does not have to be cantilever mounted.

A further object of the invention is to provide a ventilating apparatus which is easily mounted in a wall formed of rectangular shaped building unit-s.

Still a further object of the invention is to provide a ventilating apparatus which is easily and quickly partially disassembled for maintenance purposes.

Related objects and advantages will become apparent as the description proceeds.

One embodiment of this invention might include a ventilating apparatus comprising a frame defining an opening through which air may be moved. There is also provided a plurality of louvers fixed to the frame in spaced relation and extending through said opening and defining spaces between the louvers, and a plurality of back draft dampers mounted on said louvers and each controlling a respective space between the louvers.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

FIG. 1 is a perspective view of a ventilating apparatus embodying the present invention.

FIG. 2 is a view similar to FIG. 1 but taken from above and to the rear of the ventilating apparatus.

FIG. 3 is an enlarged vertical section taken along the line 3-3 of FIG. 1 in the direction of the arrows.

FIG. 4 is a still further enlarged section similar to FIG. 3 but showing the details of a louver carrying frame forming a part of the structure illustrated in FIG. 3.

FIG. 5 is an enlarged fragmentary perspective view of a spring latch forming a part of the structure illustrated in FIG. 3.

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FIG. 6 is a rear elevation of the ventilating apparatus showing it with the louver carrying frame removed.

FIG. 7 is a view similar to FIG. 4 of an alternative embodiment of the invention.

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawing and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Refer-ring now more particularly to the drawings, there is illustrated an exhaust fan 10 which includes a housing 11 having two vertical rectangular side walls 12 and two horizontal rectangular side walls 15. The housing 11 is formed with flanges 16 extending from the respective side walls, which flanges are used for mounting a volute 17 within which a centrifugal blower wheel 20 operates. As is best illustrated in FIG. 3, the blower wheel 20 sucks air into the exhaust fan through an opening 21 in the volute and moves the air radially outwardly, thence leftwardly as viewed in FIG. 3 through the housing 11 and then through a louver carrying frame 22.

The exhaust fan 10 is normally mounted in a wall as suggested in FIG. 3 and, because of the externally square-shaped configuration of the housing 11, is particularly adapted for building into a wall which is being built up by means of rectangular building units such as building blocks 30 and bricks 31. If desired, an inlet grill 32 may be provided on the inside of the building or suitable duct work may be used instead.

Referring to FIG. 3, a horizontal plate having reinforcing flanges 41 is fixed at its opposite ends to the vertical side walls 12. The horizontal plate 40 supports a motor mount 42 which mounts a motor 45 precisely within the center of the housing 11. As can be seen from FIG. 6 and the other figures, the housing 11 has a cross sectional configuration which is square-shaped so that the motor 45 is mounted with the axis of the drive shaft 46 of the motor precisely at the center of the square-shaped cross sectional configuration.

The motor mount 42 is secured to the horizontal plate 40 by means of suitable bolts which extend through resilient cushioning washers 43. The motor mount 42 includes an inverted U-shaped element 48 having a top 47 and sides 50 with outwardly projecting flanges 51 at the lower ends of the sides. A vertical plate 55 is secured to the top and sides of the U-shaped element 48 and has the motor 45 mounted directly thereon. The vertical plate 55 is formed with a central aperture 56 through which the drive shaft of the motor projects.

One of the most important features of the ventilating apparatus of the present invention is the louver carrying frame 22 which is shown in detail in FIG. 4. The frame 22 includes vertical sides and a horizontal top 71 and a horizontal bottom 72 (FIG. 3). The top, bottom and sides 70, 71 and 72 define an opening 75 through which air may be moved. A plurality of louvers 76 are fixed to the frame 22 in spaced parallel relation and extend through the opening 75, defining spaces 77 through which air may be moved by the blower Wheel 20. It will be noted that the louvers 76 extend downwardly from the interior terminus 80 of the opening 70 to the exterior terminus 81 of the opening. Thus, rain, snow and the like falling upon the louvers 76 will tend to flow downwardly along the louvers and out of the exhaust fan. Fixed to the rearward surface of the frame 22 is a bird screen 90. The bird screen functions not only to prevent birds from going into the building between the louvers 76, but also functions as a rigid backstop for back draft dampers 91. Each of the back draft dampers 91 controls backward air flow through the respective spaces 77 between the respective louvers 76. Thus, should air tend to flow rightwardly as viewed in FIG. 4 between the louvers 75, the back draft dampers 91 will engage the portions 92 of the louvers and also will move to positions closely alongside of the flanges 95 extending from the side walls 70 so as to block movement of air rightwardly as viewed in FIG. 4 through the frame 22.

As is suggested in FIG. 4, the back draft dampers 91 are flexible in nature. The back draft dampers are supported at their upper ends by the louvers and hang downwardly in the spaces 77 between the louvers. Because of the flexible nature of the back draft dampers 91, air flow in a leftward direction as viewed in FIG. 4 causes the dampers 91 to move leftwardly toward the louvers next above the back draft dampers, permitting the blower wheel 20 to move air through the spaces 77.

One important feature of the present invention is the ease with which maintenance can be accomplished upon the working parts inside of the housing. Thus, it is relatively easy to dismount the volute 17 from the housing by removing the screws 100. Also, the frame 22 can be easily removed from the housing 15 by grasping the frame at one of the louvers 76 toward the bottom of the frame and by pulling the frame leftwardly as viewed in FIG. 3, or, in other words, by pulling the frame 22 away from the housing. The frame 22 is held in position by means of a spring 101 which has a bias urging the projection 102 of the spring downwardly against the lower side wall 15 of the housing 11. The projection 102 extends between projections 105 formed in the lower side wall 15 of the housing 11 whereby the frame 22 is normally held in the position illustrated in solid lines in FIG. 3. The horizontal plate 40 acts as a limit for inward movement of the frame 22. Also, in the upper portion of the housing 11 there is provided a limit member 106 fixed to the upper side wall 15. The limit member 106 also functions to prevent or limit inward movement of the frame 22 into the housing 11. A flange 107 is formed on the upper side wall 15 at the exterior terminus 110 of the housing. The flange 107 functions to normally maintain the frame 22 within the housing.

Referring to FIG. 7, there is illustrated an alternative embodiment of the invention which is identical to the embodiment of FIGS. 1-6 except that the louver carrying frame 22 is replaced by a louver carrying frame 200. The louver carrying frame 200 is externally similar to the frame 22 in that it mounts in the housing 11 in the same fashion as the frame 22. Also, the frame 200 is provided with a bird screen 201 which is fixed to the rearward surface of the frame in the same fashion as above described. The primary ditference between the structure of FIG. 7 and FIG. 4 is the configuration of the louvers 202 as compared to the louvers 75. The louvers 202 are smoothly curved in a flat S shape but have a flange 5 which acts against the main body of the louver to mount the flexible back draft dampers 206. Similarly to the back draft dampers 91, the back draft dampers 206 have the screen 201 as a back up or back stop for blocking air flow through the spaces 207 between the louvers 202.

The dampers 206 may be coated with polyethylene and the polyethylene shrunk on the fabric to produce the curved shape illustrated in FIG. 7. This curved shape helps the dampers to better seat at their distal ends 210 against the louvers next below and also helps the dampers better seat against and fit the lower surface of the louvers upon which they are mounted to allow air flow leftwardly as viewed in FIG. 7 through the spaces 207. Because of the smooth shape of the louvers of FIG. 7, air is better able to flow smoothly, efficiently and without substantial friction through the louvers 202 than through the louvers 76.

It will be evident from the above description that the present invention provides a ventilating apparatus which is particularly adapted for wall mounting and which presents a clean appearance flush with the outside wall of a building. It will also be evident that the ventilating apparatus of the present invention provides a particularly effective and efiicient back draft damper which operates in combination with a bird screen. It will also be evident that the ventilating apparatus of the present invention provides a particularly effective means for mounting of the motor and the blower wheel in such a manner that the weight of the motor and blower wheel is supported in line with the wall upon which the ventilating apparatus is mounted instead of supporting this weight in cantilever fashion outside of the wall. A further novel feature .of the present invention is the combination of a centrifugal blower with a square housing for mounting in a wall composed of rectangular building units.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention and the scope of the claims are also desired to be protected.

The invention claimed is:

1. Ventilating apparatus comprising a frame defining an opening through which air may be moved, a plurality of louvers fixed to said frame in spaced relation and extending through said opening and defining spaces between said louvers, and a plurality of back draft dampers mounted on said louvers and each controlling a respective space between louvers, said frame having an exterior terminus and an interior terminus to said opening, said louvers having a length dimension which extends horizontally, said louvers sloping downwardly toward said exterior terminus, each of said back draft dampers being mounted on a respective one of said louvers at said interior terminus and swingingly depending from the respective louver, said ventilating apparatus having a screen secured thereto at said interior terminus, said screen acting as a limit for said back draft dampers, said back draft dampers being formed of flexible material.

2. The invention of claim 1 additionally comprising a housing of square-shaped cross section adapted for mounting in a wall, said housing having four rectangular side walls which meet adjacent side walls at right angles, two of said side Walls being vertical and two of said side walls being horizontal, said frame being received within said housing, a horizontal plate fixed at its opposite ends to said vertical side Walls and extending therebetween and positioned between said horizontal side walls, a centrifugal fan, a motor having an output shaft upon which said fan is mounted, a motor mount for said motor mounting said motor upon said plate in the center of said housing between said vertical side Walls and between said horizontal side walls, a volute mounted on said housing about said fan and having an opening at its center for guiding air into said fan and for guiding air from said fan into said square-shaped housing, said square-shaped housing acting as a duct for air moved by said centrifugal fan, and resilient cushioning means received between said motor mount and said plate.

3. The invention of claim 2 wherein said fan is a centrifugal blower wheel and said motor mount comprises an inverted U-shaped element having a top and sides with outwardly projecting flanges at the lower ends of said sides, bolts securing said flanges to said plate, said cushioning means comprising rubber grommets received on said bolts, a vertical plate secured to the top and sides of said U-shaped element, said motor being secured to said vei'tical plate and said output shaft extending 3,122,088 2/1964 Patterson 98-4'3 through said vertical plate. 3,204,546 9/1965 Krel-l 9843 X 3,236,171 2/1966 Vaskov et a1 981 14 X References Cited 3,249,038 5/1966 Johnson 98116 UN STATES PATENTS 5 3,255,688 6/1966 Iwata 98-95 2,216,420 10/1940 Rose 9895 X a 2,349,668 5/1944 Marker et a1 H 98.43 ROBERT A. O LEARY, Prlmary Exammel.

2 711 32 1955 Drechsel 4 W. E. WAYNER, Assistant Examiner. 

